Debka.com thinks that this was a screwup (h/t TPM):
The entire episode bespeaks faulty intelligence on what was going on aboard the six vessels bound for Gaza, although the information was available from daily live broadcasts and easy access to visitors.
And another question: The IDF is famous for its innovative electronic warfare capabilities. So why were the signals and images coming from the convoy not jammed as promised and allowed to reach world TV screens hours before the authorities responsible for Israeli information woke up?
And finally, why did the interception take place 80 miles out to sea in international waters, thereby fueling the complaint that Israel broke international law? The blockade zone is 20 nautical miles deep from Gaza. An Israeli raid at that limit would have been easier to justify.